Mr Lungu is asking the Lusaka High Court to review a decision made by the government that stopped him from going to South Korea.
He has submitted court documents to support his request.
His political group, the Patriotic Front (PF), has criticized the government’s reported action, describing it as against the law.
Emmanuel Mwamba, the PF’s spokesperson, said that if someone is invited and their trip expenses are covered or if they can pay for their own trip and for their entourage, they don’t have to tell the governments about it.
Mr Mwamba said the ex-president wanted to go on a medical trip, but he wasn’t allowed to go even though he asked for permission from the cabinet office.
“He said that these harsh and oppressive actions go against the basic rights of the former president and should not be a part of a real democracy. ”
Mr Lungu no longer has power, and it is now held by the current President, Hakainde Hichilema, since 2021.
He said he would stop being involved in politics, but many people think he wants to come back and might try to be elected again in 2026.